Phase separating tube

ABSTRACT

A phase separating tube having a hollow tubular member provided with an opening removably covered by a plug capable of selectively dispensing a liquid from the tubular member at variable rates of fluid flow. The plug has a rigid outer part and a flexible inner part connected to the outer part, with the inner part provided with a conical portion that cooperates with a hollow cone mounted within the tube and arranged converging toward the conical portion for selectively closing and variably opening an outlet of the cone and controlling flow from the tubular member through the outlet of the cone and into an annular channel formed in the inner part for passage out of the phaseseparating tube.

United States Patent 1 1 Yanez, Jr.

1 1 PHASE SEPARATING TUBE [75] Inventor: Mario Yanez, Jr., Miami, Fla.

[73] Assignee: Sindco Corporation, Coral Gables,

Fla.

[22] Filed: Feb. 1, 1974 [21] Appl. No.: 438,800

[52] U.S. CI. 233/26; 128/2 F [51] Int. Cl? B04B 9/12 [58] Field of Search 233/1 R, 26, 27, l A;

128/2 F, 218 D, 272, 295, DIG. 28; ZlO/DIG, 23, DIG. 24, 516

[451 Aug. 5, 1975 565,193 11/1932 Germany 233/26 Primary E.\aminerGeorge H. Krizmanich Attorney, Agent, or Firm-Clarence A. OBrien; Harvey B. Jacobson [57] ABSTRACT A phase separating tube having a hollow tubular member provided with an opening removably covered by a plug capable of selectively dispensing a liquid from the tubular member at variable rates of fluid flow. The plug has a rigid outer part and a flexible inner part connected to the outer part, with the inner part provided with a conical portion that cooperates with a hollow cone mounted within the tube and arranged converging toward the conical portion for selectively closing and variably opening an outlet of the cone and controlling flow from the tubular member through the outlet of the cone and into an annular channel formed in the inner part for passage out of the phase separating tube.

8 Claims, 4 Drawing Figures PHASE SEPARATING TUBE BACKGROUND OF THE INVENTION l. Field of the Invention This invention relates generally to a container for liquids, and particularly to a time-saving phase-separating tube that can also be used as a liquid measuring cylinder, a liquid mixing cylinder, a centrifuge tube, and a microseparatory funnel, or for any other application which requires a container capable of dispensing or retaining a measured liquid aliquot. Further, a phase separating tube according to the present invention is also capable of being used as an optical cuvet.

2. Description of the Prior Art When dealing with multiphase systems, it is often necessary and desirable to remove a separated heavy phase or phases from the bottom of the tube without going through the lighter, upper phase or phases above this heavy phase or phases. Toward this end, tubes have been proposed that permit predetermined quantities of liquid to be withdrawn from the bottom of the tube. See, for example, U.S. Pat. No. 3,081,029, issued Mar. I2, 1963 to K. Gauslaa, wherein a hypodermic needle is used to withdraw a heavier phase from the bottom of a centrifuge tube by inserting the needle through a resilient material arranged for the purpose.

US. Pat. No. 2,649,245, issued Aug. 18, l953 to K. O. L. Silverstolpe, also discloses a centrifuge tube whose construction permits predetermined quantities of liquid to be withdrawn from the bottom. In this instance, the bottom is sealed by a stopper which may be simply removed to permit an uncontrolled flow from the bottom of the tube. Rather than control the rate of fluid flow out of the tube's bottom opening by varying the size of the opening, US. Pat. No. 2,649,245 controls the air pressure within the tube for determining the flow rate out through a fixed egress opening.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a phase-separating tube, and the like, which permits precise amounts of liquid to be dispensed through the bottom of the tube.

It is another object of the present invention to provide a dispensing plug permitting a measured aliquot to be precisely dispensed from a phase-separating tube, and the like.

These and other objects are achieved according to the present invention by providing a phase-separating tube having: a hollow member provided with an opening and arranged for holding a predetermined quantity of a liquid; a plug arranged covering the opening; and an inner part of the plug forming a dispensing arrangement including a conical portion disposed for selectively mating with an outlet of a cone arranged with the tube for selectively dispensing liquid from the hollow member at variable rates of flow.

According to a preferred embodiment of a dispensing plug according to the present invention, the inner part is constructed from a flexible material and has: a hollow cylindrical portion provided with an internal wall defining a flow path from an end of the cylindrical portion arranged adjacent the inner cone of the hollow member through and to an end of the cylindrical portion forming an outlet of the plug; a conical portion connected to the cylindrical portion at the end thereof adjacent the inner cone and arranged for sealing engagement with an outlet of the inner cone; and a rod connected to the conical portion and arranged extending coaxially through the cylindrical portion toward the outlet end thereof for forming an annulus in cooperation therewith. A substantially hemispherical portion is provided at the outlet end of the cylindrical portion for mating with a receiving part of a centrifuge, and the like, and distributing the pressure evenly on the bottom of the tube when centrifuged. This pressure will help make the sealing tighter as the centrifugal force increases.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a phaseseparating tube according to the present invention.

FIG. 2 is a sectional view taken generally along the line 2-2 of FIG. 1, but drawn to a larger scale.

FIG. 3 is a sectional view taken generally along the line 3-3 of FIG. 2.

FIG. 4 is a perspective view showing a dispensing plug according to the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now more particularly to the drawings, a phase-separating tube 10 according to the present invention has a hollow member in the form of a tubular member or tube 12 provided with a pair of spaced, threaded open ends. Tube 12 is arranged for holding a predetermined quantity of a liquid received generally through the upper open end and dispensed through the bottom open end. The latter forms an opening 14 conveniently provided with conventional screw threads for receiving a dispensing plug 16 arranged removably covering opening 14. A cap 18 is advantageously removably arrangeable on the other or upper of the open ends of tube 12 in a conventional manner, as by the illustrated screw threads. A hollow cone 20 is mounted within tube 12 and is arranged converging toward opening 14; terminating in an outlet opening at the closest point to opening 14.

Tube 12 may be constructed in a suitable, known manner from glass or a chemically resistant synthetic material. lndicia are advantageously made on tube 12 in a conventional manner for graduating the tube in conventional scales. A, for example, milliliter graduation from the bottom of the cylinder 21 below the cone 20 to the upper or top end of tube 12 is illustrated in FIG. 1 of the drawings. Cone 20 is advantageously provided with a cylindrical or stem portion 21 of a length sufficient to permit easy observation of the interphase of two immiscible liquids, and sufficiently wide and short so that no liquid or gas bubbles are trapped in cone 20 when emptying or filling the tube.

Plug 16 is formed by cooperating outer rigid part 22 and flexible inner part 24 connected together in a manner to be described below. Inner part 24 is constructed in such a manner that it functions as a valve for opening and closing the outlet opening formed by the end of stem 21.

Included in inner part 24 are a hollow cylindrical portion 26 having an internal wall 28 defining a flow path from an end 30 of the cylindrical portion 26 adjacent cone through cylindrical portion 26 and to an outlet end 32 of same forming an outlet of plug 16. A conical portion 34 is connected to the cylindrical portion 26 at end thereof, and is arranged for sealing engagement with the outlet of stem 21 of cone 20. A rod 36 is connected to the conical portion 34 and arranged extending coaxially through cylindrical portion 26 toward outlet end 32, as can best be seen in FIG. 2 of the draw ings. The connection of rod 36 and conical portion 34 to cylindrical portion 26 is achieved by using a plurality, three being shown, of members 38 which cooperate to form a spider best seen in FIG. 3 of the drawings. These members 38 are connected to and extend between cylindrical portion 26 and, desirably, conical portion 34.

Inner part 24 further includes a substantially hemispherical portion 40 provided at outlet end 32 of cylindrical portion 26 for fitting in a receiving part of a centrifuge (not shown) in a conventional manner.

Sealing rings 42 and 44 are advantageously arranged around cylindrical portion 26 between conical portion 34 and hemispherical portion 40 for sealing plug l6 to tube 12 when conical portion 34 is spaced from the outlet of stem 2]. Respective grooves 46 and 48 are provided around the periphery of cylindrical portion 26 immediately adjacent sealing rings 42 and 44 in the direction toward hemispherical portion 40 for permitting deformation of sealing rings 42 and 44 when same are pressing against the inner wall of the threaded portion of tube 12. In this manner, it is assured that no liquid will leak around the edge of opening 14 and past the screw threads fastening plug 16 to the tube.

inner part 24 may be constructed from any suitable, known flexible synthetic material, such as polyethylene, that has desirable parameters, such as the requisite flexibility and appropriate chemical inertness. Outer part 22 of plug 16 may be constructed from any suitable, known rigid synthetic material, such as a polyvinyl resin, as may cap l8.

Outer part 22 includes a substantially cylindrical sleeve 50 provided with an inwardly directed, annular flange S2 at one end thereof. Inner part 24 is further provided with an annular lip 54 extending from cylindrical portion 26 adjacent to and spaced from a planar surface of hemispherical part 40. Flange S2 is arranged between lip 54 and this planar surface for retaining outer part 22 to inner part 24. In this manner, the two parts 22 and 24 are securely held together.

Sleeve 50 as well as the cylindrical portion of cap 18 may be provided with vertically extending ridges, and the like, for facilitating manipulation of their respective elements.

OPERATION With the lower end plug 16 screwed all the way onto tube 12 so that the tip of cone 20 is sealed by conical portion 34, and with tube 12 in a vertical position, immiscible liquids may be poured into tube 12 through the upper end; cap 18 having been removed. Cap 18 is now replaced on the upper end of tube 12, and the entire tube is shaken so as to afford the greatest Contact between the two or more immiscible phases. Once the liquids have been well shaken, tube 12 is placed in a conventional centrifuge (not shown), and the like, and

centrifuged at a specified speed and time so as to adequately separate the immiscible liquid phases. After the phases have been separated, tube 12 is removed from the centrifuge, and with tube 12 in a vertical position, the upper screw cap 18 is loosened. With tube 12 still in a vertical position, plug 16 is slowly unscrewed so as to break the seal on the outlet of stem 21 of cone 20 by moving conical portion 34 away therefrom, and the lower, or heaviest immiscible liquid phase is allowed to flow by gravity out of cone 20 through stem 21 and onto the upper part of rod 36 so that it traverses the hollow portion of plug 16 along the surface of rod 36 until it drips from the tip of rod 36 into a suitable container (not shown). The rate of flow of the liquid is controlled by the degree of rotation of plug 16, which will result in a gradual opening of the seal on the tip of stem 21 of cone 20. The volume of liquid flowing out of the tube can be measured by visually following the position of the menisci as they descend along the graduated scale formed by the indicia on tube 12.

A phase-separating tube 10 according to the present invention will permit the following studies to be made: (a) liquid-liquid extraction and separation of the immiscible phases. (b) Centrifugation of an emulsion and separation of its components after breaking up the emulsion. (c) An aliquot of the lower immiscible liquid phase may be obtained for further study. (cl) An aliquot of the upper immiscible phase may be obtained for further study, after the lower phase has been discarded. (e) Either the upper or the lower phase may be reacted inside the tube and the product of the reaction, or the unreacted phase itself, may be detected by an appropriate instrument such as a spectrophotometer, fluorometer, and the like, by utilizing tube 10 as an optical cuvet.

Phase separating tube 10 may be used as an optical cuvet by making the distance from the upper rim of the cone 20 to the bottom of plug 16 such that when tube 10 is placed in the call cavity (not shown) of a spectrophotometer, and the like, light will pass above cone 20 and through the unobscured cylindrical wall of tube 12.

As can be appreciated from the above description and from the drawings a phase-separating tube 10 according to the present invention provides a time-saving device for separating liquids into their respective phases, and also permits a single apparatus to be used as a liquid measuring cylinder, a liquid mixing cylinder, a centrifuge tube, a microseparatory funnel, and for any other application requiring apparatus capable of dispensing or retaining a measured liquid aliquot. Further, the apparatus may also be used as an optical cuvet.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.

What is claimed as new is as follows:

1. A phase-separating tube, comprising, in combination:

a. a hollow member provided with an opening and arranged for holding a predetermined quantity of a liquid;

b. a plug arranged selectively covering the opening;

and

c. means for selectively dispensing liquid from the hollow member at variable rates of flow, the hollow member being provided with a cone mounted within the hollow member and arranged converging toward the opening thereof, the plug having an outer rigid part and a flexible inner part, the inner part forming the means for dispensing, and including:

i. a hollow cylindrical portion having an internal wall defining a flow path from an end of the cylindrical portion adjacent the cone through the cylindrical portion and to an end thereof forming an outlet of the plug;

ii. a conical portion connected to the cylindrical portion at the end thereof adjacent the cone and arranged for sealing engagement with an outlet of the cone; and

iii. a rod connected to the conical portion and arranged extending coaxially through the cylindrical portion toward the outlet forming end thereof, whereby the rod forces the flow ofliquid along its surface. preventing any liquid flow on the internal wall of the hollow cylindrical portion and the wetting of the outer rim of the outlet where potentially hazardous liquids may otherwise come in contact with the hands of the operator or any other surface.

2. A structure as defined in claim I, wherein the hollow member is tubular and has a pair of spaced, open ends, one of the open ends forming the opening, and

further including a cap removably arrangeable on the other of the open ends of the hollow member.

3. A structure as defined in claim 1, wherein the cone and a cylindrical portion attached to it form a funnel that provides an increased precision in separating two immiscible liquids by permitting an easy observation of the moving interphase.

4. A phase-separating tube, comprising, in combination:

a. a hollow member provided with an opening and arranged for holding a predetermined quantity of a liquid;

b. a plug arranged selectively covering the opening;

and

c. means for selectively dispensing liquid from the hollow member at variable rates of flow, the hollow member being tubular and having a pair of spaced, open ends, one of the open ends forming the open ing, and further including a cap removably arrangeable on the other of the open ends of the hollow member, the hollow member being further provided with a cone mounted within the hollow member and arranged converging toward the opening thereof, whereby the cone and a cylindrical portion attached to it form a funnel that provides an in creased precision in separating two immiscible liquids by permitting an easy observation of the moving interphase, and the plug having an outer rigid part and a flexible inner, part, the inner part forming the means for dispensing, and including:

i, a hollow cylindrical portion having an interna wall defining a flow path from an end of the cylindrical portion adjacent the cone through the cylindrical portion and to an end thereof forming an outlet of the plug;

ii. a conical portion connected to the cylindrical portion at the end thereof adjacent the cone and arranged for sealing engagement with an outlet of the cone; and

iii. a rod connected to the conical portion and arranged extending coaxially through the cylindrical portion toward the outlet forming end thereof, whereby the rod forces the flow of liquid along its surface, preventing any liquid flow on the internal wall of the hollow cylindrical portion and the wetting of the outer rim of the outlet where potentially hazardous liquids may otherwise come in contact with the hands of the opera tor or any other surface.

5. A structure as defined in claim 4, wherein the inner part further includes a substantially hemispherical portion provided at the outlet forming end of the cylindrical portion, where in addition to providing a resting portion for the tube that protects the seal, the hemispherical portion also provides a means of evenly distributing the pressure generated while centrifuging which at the same time helps maintain the seal.

6. A structure as defined in claim 5, wherein at least one sealing ring is arranged around the cylindrical portion between the conical portion and the hemispherical portion for sealing the plug to the hollow member when the conical portion is spaced from the cone outlet, and a groove provided around the periphery of the cylindrical portion immediately adjacent the sealing ring in the direction of the hemispherical portion for permitting deformation of the sealing ring when same is pressing against the hollow member, the arrangement prevent ing any leakage of potentially hazardous liquid through the threads when the seal is open.

7. A structure as defined in claim 6, wherein the outer part is a substantially cylindrical sleeve provided with an inwardly directed, annular flange at a one end of the sleeve, and the inner part is further provided with an annular tip arranged extending from the cylindrical portion adjacent to and spaced from a planar surface of the hemispherical portion, the flange being arranged between the lip and planar surface for retaining the outer part to the inner part, and means provided on the outer part for fastening the plug to the hollow member in a variable relationship with respect thereto, the inner part annular lip also serving as a cushion for protecting the rim of the hollow member from breakage while centrifuging.

8. A structure as defined in claim 7, wherein the conical portion is connected to the cylindrical portion by a plurality of spaced members connected to and extending between the cylindrical portion and conical portion for forming a spider. 

1. A phase-separating tube, comprising, in combination: a. a hollow member provided with an opening and arranged for holding a predetermined quantity of a liquid; b. a plug arranged selectively covering the opening; and c. means for selectively dispensing liquid from the hollow member at variable rates of flow, the hollow member being provided with a cone mounted within the hollow member and arranged converging toward the opening thereof, the plug having an outer rigid part and a flexible inner part, the inner part forming the means for dispensing, and including: i. a hollow cylindrical portion having an internal wall defining a flow path from an end of the cylindrical portion adjacent the cone through the cylindrical portion and to an end thereof forming an outlet of the plug; ii. a conical portion connected to the cylindrical portion at the end thereof adjacent the cone and arranged for sealing engagement with an outlet of the cone; and iii. a rod connected to the conical portion and arranged extending coaxially through the cylindrical portion toward the outlet forming end thereof, whereby the rod forces the flow of liquid along its surface, preventing any liquid flow on the internal wall of the hollow cylindrical portion and the wetting of the outer rim of the outlet where potentially hazardous liquids may otherwise come in contact with the hands of the operator or any other surface.
 2. A structure as defined in claim 1, wherein the hollow member is tubular and has a pair of spaced, open ends, one of the open ends forming the opening, and further includinG a cap removably arrangeable on the other of the open ends of the hollow member.
 3. A structure as defined in claim 1, wherein the cone and a cylindrical portion attached to it form a funnel that provides an increased precision in separating two immiscible liquids by permitting an easy observation of the moving interphase.
 4. A phase-separating tube, comprising, in combination: a. a hollow member provided with an opening and arranged for holding a predetermined quantity of a liquid; b. a plug arranged selectively covering the opening; and c. means for selectively dispensing liquid from the hollow member at variable rates of flow, the hollow member being tubular and having a pair of spaced, open ends, one of the open ends forming the opening, and further including a cap removably arrangeable on the other of the open ends of the hollow member, the hollow member being further provided with a cone mounted within the hollow member and arranged converging toward the opening thereof, whereby the cone and a cylindrical portion attached to it form a funnel that provides an increased precision in separating two immiscible liquids by permitting an easy observation of the moving interphase, and the plug having an outer rigid part and a flexible inner, part, the inner part forming the means for dispensing, and including: i. a hollow cylindrical portion having an internal wall defining a flow path from an end of the cylindrical portion adjacent the cone through the cylindrical portion and to an end thereof forming an outlet of the plug; ii. a conical portion connected to the cylindrical portion at the end thereof adjacent the cone and arranged for sealing engagement with an outlet of the cone; and iii. a rod connected to the conical portion and arranged extending coaxially through the cylindrical portion toward the outlet forming end thereof, whereby the rod forces the flow of liquid along its surface, preventing any liquid flow on the internal wall of the hollow cylindrical portion and the wetting of the outer rim of the outlet where potentially hazardous liquids may otherwise come in contact with the hands of the operator or any other surface.
 5. A structure as defined in claim 4, wherein the inner part further includes a substantially hemispherical portion provided at the outlet forming end of the cylindrical portion, where in addition to providing a resting portion for the tube that protects the seal, the hemispherical portion also provides a means of evenly distributing the pressure generated while centrifuging which at the same time helps maintain the seal.
 6. A structure as defined in claim 5, wherein at least one sealing ring is arranged around the cylindrical portion between the conical portion and the hemispherical portion for sealing the plug to the hollow member when the conical portion is spaced from the cone outlet, and a groove provided around the periphery of the cylindrical portion immediately adjacent the sealing ring in the direction of the hemispherical portion for permitting deformation of the sealing ring when same is pressing against the hollow member, the arrangement preventing any leakage of potentially hazardous liquid through the threads when the seal is open.
 7. A structure as defined in claim 6, wherein the outer part is a substantially cylindrical sleeve provided with an inwardly directed, annular flange at a one end of the sleeve, and the inner part is further provided with an annular tip arranged extending from the cylindrical portion adjacent to and spaced from a planar surface of the hemispherical portion, the flange being arranged between the lip and planar surface for retaining the outer part to the inner part, and means provided on the outer part for fastening the plug to the hollow member in a variable relationship with respect thereto, the inner part annular lip also serving as a cushion for protecting the rim of the hollow member from breakage while centrifuging.
 8. A structure as defined in cLaim 7, wherein the conical portion is connected to the cylindrical portion by a plurality of spaced members connected to and extending between the cylindrical portion and conical portion for forming a spider. 